Waste material is everywhere and numerous efforts have been taken to find ecologically and economically justified solutions to address this challenge.
A typical example of waste material are paper related products, among others, finding its origin in the label manufacturing. Self adhesive labels, films, and tapes have become very popular for their versatility and ease of use, since no extra glue is required to make them adhere to a substrate. They are used extensively in offices and by school children of course, but also large volumes are used by industries for labelling their products. The self-adhesive labels are provided attached to a release liner made of paper or a polymeric carrier and usually coated at least on one side with a release agent, most often consisting of a silicone release layer, which provides a release effect against the adhesive of the label. Other release agents are sometimes used, such as wax, paraffin, low surface energy fluorinated compounds, etc. Examples of silicone coated liners are given in U.S. Pat. No. 5,275,855, JP07279099, and U.S. Pat. No. 6,036,234. Silicone or other release agent coated liners are also used more generally as backing in the production of films, such as PVC films. The total global consumption of release liners in 2008 is believed to be around 32 Billion square meter of coated product, which is equal to 75% of the surface area of Switzerland. Approximately 85% of this material is paper based and 15% is plastic based (cf. http://en.wikipedia.org/wiki/Release_liner).
After use of the labels, films or tapes supported on said carriers, the liners are pure waste and must be disposed of. Considering the volumes mentioned above, there is a great source of waste, which is coming under the scrutiny of several governments which intend to tax the disposal thereof as packaging material. The building and transportation industries are making more and more use of cellulose materials coming from old newspaper, cardboard, etc. to manufacture heat and acoustic insulating materials in the form of loose fibrous materials, fibrous mats with or without skins, panels of varying stiffness, and even hollow blocks; the manufacture of blocks and panels may require the use of a binder, a glue or a cement.
Next to paper waste material, products made from or incorporating plastic and or rubber materials are part of almost any aspect of daily life. Some of the prevalent primary polymer types in the waste plastic materials are ABS, HIPS, PP, PET and PC. Generally, the plastic or rubber materials that are used to create these products are formed from virgin plastic materials that are produced from petroleum and are not made from existing stock. Literally millions of tons of plastic and rubber are produced and consumed each year. Recycling plastic materials obviates the need for disposing of the plastic materials or product. Further, in an era of reduced and more expensive petroleum material cost, the expense of production of the plastic is reduced as less further petroleum is necessary for the production. When plastic materials are sent to be recycled, the feed streams rich in plastics may be separated into multiple product and by product streams. Generally, the recycling processes can be applied to a variety of plastics-rich streams derived from post-industrial and post-consumer sources. For example, these streams may include plastics from office automation equipment (printers, computers, copiers, etc.), white goods (refrigerators, washing machines, etc.), consumer electronics (televisions, video cassette recorders, stereos, etc.), consumables (diapers, plastic utensils, plastic cups, etc.), automotive shredder residue, packaging waste, household waste, building waste and industrial scrap (molding, non-woven, fiber, extrusions, etc.). There continues to be a need for systems and methods that will further improve the efficiency with which waste plastic and rubber materials are reclaimed and the quality of the resultant reclaimed plastic. In particular, there is a continuing need for systems and methods that are useful for processing waste plastic material from any prospective plastic waste stream into reclaimed polymeric materials. Many variations exist, depending on at least the nature of the shredding operation. Plastics from more than one source of durable goods may be including in the mix of materials fed to a plastics recycling plant, which means that a very broad range of plastics may be included as potential sources of waste plastic material.
From the above it is clear that there remains in the art a need for finding and stimulating routes to recycle waste material. In parallel, there remains a lot to do in the fields of recycled waste material such as paper and of insulation materials for the building, transportation, and other industries to provide a new application/new product, via an environmentally, economically viable and sustainable route, thereby providing acceptable properties such as meeting specifications required for a given application.
The present invention now proposes a solution to these and other problems in the art of recycling.